scholarly journals Five Years (2014–2018) of Beta Activity Concentration and the Impact of Synoptic and Local Meteorological Conditions in Bilbao (Northern Spain)

Atmosphere ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1323
Author(s):  
Natalia Alegría ◽  
Miguel Ángel Hernández-Ceballos ◽  
Margarita Herranz ◽  
Raquel Idoeta ◽  
Fernando Legarda
Keyword(s):  
Surface Activity ◽  
Ground Level ◽  
Beta Activity ◽  
Northern Spain ◽  
Gross Beta ◽  
Factors Affecting ◽  
Wind Speeds ◽  
Activity Concentrations ◽  
Low Wind Speeds ◽  
The Impact

The aim of this paper is to statistically characterize gross beta activity concentrations in ground-level air in Bilbao (northern Spain) by analysing five years (2014–2018) worth of weekly measurements in aerosols collected in filters to analyse the impact of local meteorological parameters on concentrations. In addition, synoptic meteorological scenarios associated with anomalous beta surface activity concentrations were identified. Over this five-year period, beta activity concentrations ranged from 35.45 µBq/m3 to 1778 µBq/m3 with a mean of 520.12 ± 281.77 µBq/m3. A positive correlation was found with the alpha concentrations (0.67), with an average of 0.138 for the alpha/beta ratio, and a low correlation was found with 7Be (0.16). Statistical analysis identified a seasonal component in the time series, increasing, on average, beta activity concentrations from winter to autumn. The highest beta activity concentrations were measured under the arrival of southerly land winds with low wind speeds, while the wind analysis (surface winds and air masses) of two different seasonal periods (autumn 2015 and winter 2017) have highlighted how small variations in synoptic and local winds highly influence beta activity concentrations. These results are relevant to understand the meteorological factors affecting beta activity concentrations in this area and hence to define meteorological scenarios that are in favour to high/anomalous surface activity concentrations that are harmful to the environmental and public health.

scholarly journals Analysis of Alpha Activity Levels and Dependence on Meteorological Factors over a Complex Terrain in Northern Iberian Peninsula (2014–2018)

2020 ◽  
Vol 17 (21) ◽  
pp. 7967
Author(s):  
Miguel Ángel Hernández-Ceballos ◽  
Fernando Legarda ◽  
Natalia Alegría
Keyword(s):  
Meteorological Factors ◽  
Ground Level ◽  
Alpha Activity ◽  
Activity Levels ◽  
Northern Spain ◽  
Factors Affecting ◽  
The North ◽  
Activity Concentrations ◽  
Ambient Concentrations ◽  
Alpha Peak

Alpha ambient concentrations in ground-level air were measured weekly in Bilbao (northern Spain) by collecting aerosols in filters between 2014 and 2018. Over this period, the alpha activity concentrations in the aerosol’s samples range from 13.9 µBq/m3 to 246.5 µBq/m3, with a mean of 66.49 ± 39.33 µBq/m3. The inter-annual and intra-annual (seasonal and monthly) variations are analyzed, with the highest activity in autumn months and the lowest one in winter months. Special attention has been paid to alpha peak concentrations (weekly concentrations above the 90th percentile) and its relationship with regional meteorological scenarios by means of air mass trajectories and local meteorological parameters. The meteorological analysis of these high alpha concentrations has revealed two airflow patterns-one from the south with land origin and one from the north with maritime origin-mainly associated with these alpha peak concentrations. Surface winds during representative periods of both airflow patterns are also analyzed in combination with 222Rn concentrations, which demonstrated the different daily evolution associated with each airflow pattern. The present results are relevant in understanding trends and meteorological factors affecting alpha activity concentrations in this area, and hence, to control potential atmospheric environmental releases and ensure the environmental and public health.

scholarly journals Traffic Density-Related Black Carbon Distribution: Impact of Wind in a Basin Town

2021 ◽  
Vol 18 (12) ◽  
pp. 6490
Author(s):  
Borut Jereb ◽  
Brigita Gajšek ◽  
Gregor Šipek ◽  
Špela Kovše ◽  
Matevz Obrecht
Keyword(s):  
Black Carbon ◽  
Carbon Concentration ◽  
Ground Level ◽  
Traffic Density ◽  
Carbon Distribution ◽  
Wind Speeds ◽  
Black Carbon Concentration ◽  
Low Wind Speeds ◽  
Temperature Inversions ◽  
Carbon Concentrations

Black carbon is one of the riskiest particle matter pollutants that is harmful to human health. Although it has been increasingly investigated, factors that depend on black carbon distribution and concentration are still insufficiently researched. Variables, such as traffic density, wind speeds, and ground levels can lead to substantial variations of black carbon concentrations and potential exposure, which is even riskier for people living in less-airy sites. Therefore, this paper “fills the gaps” by studying black carbon distribution variations, concentrations, and oscillations, with special emphasis on traffic density and road segments, at multiple locations, in a small city located in a basin, with frequent temperature inversions and infrequent low wind speeds. As wind speed has a significant impact on black carbon concentration trends, it is critical to present how low wind speeds influence black carbon dispersion in a basin city, and how black carbon is dependent on traffic density. Our results revealed that when the wind reached speeds of 1 ms−1, black carbon concentrations actually increased. In lengthy wind periods, when wind speeds reached 2 or 3 ms−1, black carbon concentrations decreased during rush hour and in the time of severe winter biomass burning. By observing the results, it could be concluded that black carbon persists longer in higher altitudes than near ground level. Black carbon concentration oscillations were also seen as more pronounced on main roads with higher traffic density. The more the traffic decreases and becomes steady, the more black carbon concentrations oscillate.

scholarly journals Experimental Study of Drop Impact on Deep-Water Surface in the Presence of Wind

2018 ◽  
Vol 48 (2) ◽  
pp. 329-341 ◽  
Author(s):  
Xinan Liu
Keyword(s):  
Deep Water ◽  
Water Surface ◽  
Water Drop ◽  
Threshold Value ◽  
Impact Angle ◽  
Drop Impact ◽  
Wind Speeds ◽  
Secondary Droplets ◽  
Low Wind Speeds ◽  
The Impact

AbstractThe effects of wind on the impact of a single water drop on a deep-water surface are studied experimentally in a wind tunnel. Experiments are performed by varying impacting drop diameters, ranging from 2.5 to 4.1 mm and wind speeds up to 6.7 m s−1. The sequence of splashing events that occurred during drop impacts is recorded with a backlit, cinematic shadowgraph technique. The experimental results show that for low wind speeds, an asymmetrical crown forms on the leeward of the periphery of the colliding region after the drop hits the water surface, while a wave swell forms on the windward. Secondary droplets are generated from the crown rim. For high wind speeds with large drop diameters, ligaments are generated from the crown rim on the leeward of the drop impact site. The ligaments grow, coalesce, and fragment into secondary droplets. It is found that both the drag force and surface tension play important roles in the evolution process of the ligaments. The nondimensional K number (K = WeOh−0.4, where We is the Webber number and Oh is the Ohnesorge number) is used to describe the splashing-deposition limit of drop impact. The threshold value of this K number changes with the wind velocity and/or drop impact angle.

scholarly journals Meteorological Factors Controlling 7Be Activity Concentrations in the Atmospheric Surface Layer in Northern Spain

Atmosphere ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1340
Author(s):  
Natalia Alegría ◽  
Miguel Ángel Hernández-Ceballos ◽  
Margarita Herranz ◽  
Raquel Idoeta ◽  
Fernando Legarda
Keyword(s):  
Atmospheric Surface Layer ◽  
Meteorological Parameters ◽  
Meteorological Factors ◽  
Back Trajectory ◽  
Monthly Variation ◽  
Northern Spain ◽  
Surface Level ◽  
Analysis Techniques ◽  
Activity Concentrations ◽  
The Impact

This work presents the analysis of weekly 7Be activity concentrations in the air measured in Bilbao (northern Spain) by collecting aerosols in filters over a ten years period (2009–2018). 7Be level is in the 0.35–7.3 mBq/m3 range, with a mean of 3.20 ± 1.12 mBq/m3. The trend, cycle, seasonal and monthly variability are evaluated using time series analysis techniques. The results indicate the impact of sunspots (24th solar cycle) on interannual 7Be activity concentrations, and a significant seasonal and monthly variation, with maximum concentrations occurring in spring-summer and minimum in the winter. The correlation of different 7Be ranges with local meteorological parameters, such as precipitation, temperature, relative humidity, and pressure, is also addressed, with precipitation having the greatest impact on 7Be activity values. The analysis of synoptic airflows, by calculating the back-trajectory clusters, and local winds at surface level reveals the important influence of the arrival of slow northwest Atlantic flows and the development of breezes on reaching high 7Be activity concentrations in this area.

scholarly journals Impact of the Aral Sea Syndrome - the Aralkum as a Man-Made Dust Source

2019 ◽  
Vol 99 ◽  
pp. 03003
Author(s):  
Christian Opp ◽  
Michael Groll ◽  
Oleg Semenov ◽  
Natalya Vereshagina ◽  
Asia Khamzina
Keyword(s):  
Temporal Dynamics ◽  
Monitoring Program ◽  
Ground Level ◽  
Aral Sea ◽  
Storm Events ◽  
Dust Deposition ◽  
Dust Source ◽  
Dust Transport ◽  
Wind Speeds ◽  
The Impact

Ground based dust monitoring is an important tool for the long-term monitoring of aeolian sediment transport in Central Asia as it provides valuable insights into the spatial and temporal dynamics of dust deposition as well as grants access to the transported material for further analyses. Between 2006 and 2012 such a monitoring was carried out in the Turan lowland to analyze the effects of the newly formed Aralkum. The detected spatial and temporal dust deposition variability was significant and encourages further studies. The dust deposition increased over time, which correlates with a decreasing trend in precipitation, increasing wind speeds and a shift towards northern winds. More than 50% of all dust samples collected exceed the health based deposition threshold and the most intense dust storm events reached ground level deposition rates of up to 150 g/m2 per hour. This study showed the impact of the Aralkum, but also that the Kyzylkum is a far more active dust source. With regard to climate change and an increasing aridity in the region it can be expected that the aeolian dust transport will continue to increase, making a wide-spread monitoring program even more important.

Measurement of gross alpha and gross beta activity concentrations in human tooth

2010 ◽  
Vol 101 (3) ◽  
pp. 226-229 ◽  
Author(s):  
Ömer Söğüt ◽  
Mehmet Fatih Aydın ◽  
Erdal Küçükönder ◽  
Özlem Selçuk Zorer ◽  
Mahmut Doğru
Keyword(s):  
Human Tooth ◽  
Beta Activity ◽  
Gross Beta ◽  
Gross Alpha ◽  
Gross Beta Activity ◽  
Activity Concentrations

scholarly journals Comparison of two different methods for gross alpha and beta activity determination in water samples

2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Marija M. Janković ◽  
Nataša B. Sarap ◽  
Gordana K. Pantelić ◽  
Dragana J. Todorović
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Screening Procedure ◽  
Beta Activity ◽  
Gross Beta ◽  
Gross Alpha ◽  
Preliminary Screening ◽  
Activity Determination ◽  
Activity Concentrations ◽  
Gross Alpha And Beta

AbstractMeasurement of the gross alpha and beta activity concentrations in various matrices is suitable as a preliminary screening procedure to determine whether further analysis related to specific radionuclide is necessary. In Serbia, according to current regulations, radioactivity concentrations in drinking water for gross alpha and gross beta should be < 0.5 and < 1.0 Bq L

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